Snap lock assembly

ABSTRACT

A first member has spaced openings formed therein, said openings each being defined by a rigid portion on one side and the end of a resilient tongue on the other side. Each rigid portion includes a beveled leading edge surface and an inner surface that terminates forming a gripping shoulder. A second member has yieldable projections formed and arranged for engagement with an insertion into the openings of the first member. Each projection has an enlarged end portion defined by an inclined surface formed on a side of the projection adjacent a rigid portion of the first member. The inclined surface terminates abruptly to form a lip for engaging the gripping shoulder of the first member. After insertion of the projections into the openings, the lips engage the gripping shoulders and the resilient tongues engage the projections on a side opposite the inclined surface to prevent disengagement of the lips and gripping shoulders and removal of the projections.

United States Patent [191 Crellin, Jr.

[ SNAP LOCK ASSEMBLY [75] Inventor: John R. Crellin, Jr., Spencertown,

[73] Assignee: Albany International Corp., Albany,

[22] Filed: Nov. 17, 1971 [21] Appl. No.: 199,621

[52] US. Cl 242/l.l8.6, 242/1181, 242/1187,

285/DIG. 22, 287/20 R, 287/5203 [51] Int. Cl B65h 75/14 [58] Field ofSearch 242/118.6, 118.61,

242/1187, 118.8, 118.4, 118.5, 118.1, l18.1l,1l8, 118.62, 71.8, 77.3,77.4; 287/20R, 52.03; 285/162, 82, 81, DIG. 22

Great Britain 242 11817 Jan. 15, 1974 Primary Examiner-George F. MautzAttorney-David S. Kane et a1.

[ 57] ABSTRACT A first member has spaced openings formed therein, saidopenings each being defined by a rigid portion on one side and the endof a resilient tongue on the other side. Each rigid portion includes abeveled leading edge surface and an inner surface that terminatesforming a gripping shoulder. A second member has yieldable projectionsformed and arranged for engage ment with an insertion into the openingsof the first member. Each projection has an enlarged end portion definedby an inclined surface formed on a side of the projection adjacent arigid portion of the first member. The inclined surface terminatesabruptly to form a lip for engaging the gripping shoulder of the firstmember. After insertion of the projections into the openings, the lipsengage the gripping shoulders and the resilient tongues engage theprojections on a side opposite the inclined surface to preventdisengagement of the lips and gripping shoulders and removal of theprojections.

7 Claims, 7 Drawing Figures PAIENIE JAN 1 51914 SHEUIOFZ SNAP LOCKASSEMBLY BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to connecting means and more particularly to aconnecting means having a locking action to prevent disconnection.

2. Description of the Prior Art Heretofore, various means have beenemployed for connecting components of mechanical assemblies such as thebarrel and flanges of a spool. The most common connecting methods wereadhesive cementing or solvent welding, however; these operations werelimited to certain special plastic materials. In some cases the mostdesirable material could not be used because it was not practical. Theaforementioned operations require the use of materials which pose a firehazard and sometimes involve noxious fumes; also, the resultingassembled part is not subject to immediate use because the joint must begiven time to dry in order to develop full strength. This may take aslong as two or three days resulting in considerable inventory of curingparts which during this time give off the flammable and noxious fumes.Nevertheless, many types of materials have been used with success usingthese methods.

It is also known that spin welding may be used for assembling somecircular jointed parts, however, this requires expensive machinery andfixturing.

Sonic welding is also a method which may be used to assemble plasticparts but this also requires extensive fixturing and costly sonicvibration generators. This method suffers the added disability that someparts and materials do not respond well to the sonic method.

In order to overcome the disadvantages of the previously mentionedconnecting means, components were molded with connecting arrangementsthat did not require extensive and costly machinery, substantialoperator skill, solvents or adhesives, Most of these connectingarrangements required a first motion to engage a connecting means and asecond motion to lock the connecting means. In one such device,projections from a first member were inserted into receiving means in asecond member and thereafter the members were rotated to engage alocking means. Undoubtedly, this type of device provided an improvedconnection; however, the assembly procedure required atwo-stepoperation. The members were first pressed together and then rotatedrelative to each other. This type of connecting device was limited toassemblies wherein the connecting device could be arranged in a circularpattern to provide for relative rotation. Thus, this type of devicecould not be conveniently used where square or rectangular shapedcomponents were used.

SUMMARY OF THE INVENTION The present invention contemplates a connectingassembly having means for locking the connecting assembly to preventseparation of the connected components. Connection is made by merelypressing one component into another, and the connection does not requirea second locking motion or the use of extensive and costly machinery,substantial operator skill, solvents or adhesives.

Spaced slots are formed in one of two members to be connected and theother member has projections formed and arranged for insertion into theslots of the first member. Each slot in the first member is defined onone side by the end of a resilient tongue and on the other side by arigid portion having a beveled leading edge surface and an innersurface, which terminates abruptly to form a gripping shoulder. Eachprojection of the second member has an enlarged end portion on one sidedefined by an inclined surface rising from the outermost end of theprojection and by a lip spaced inwardly from the outermost end of theprojection.

Strengthening ribs are formed adjacent each resilient tongue to increasethe strength of the first member in the areas adjacent the tongues.Formed on and extending from the strengthening ribs are fin likemembers, which engage and support the second member to prevent excessivestrain from being exerted upon the projections of the second member whena force is applied to either of the members.

The connection between the first and second members is made by merelypressing the projections of the second member into the slots of thefirst member. Initially, the inclined surfaces of the second memberengage the beveled surfaces of the first member forcing the projectionsto yield in a direction so as to engage the resilient tongues which benduntil the inclined surfaces of the second member clear the grippingshoulders of the first member so that the lips of the second memberengage the shoulders of the first member, at which point the projectionsrecover to their normal unyielded position and the resilient tonguessnap in place engaging a side of each projection opposite the inclinedsurface. The tongues prevent the projections from bending and assure acontinuous engagement of the lip with the gripping shoulder of the firstmember.

The primary objective of the present invention is to provide aconnecting device including a locking means.

Another objective of the present invention is to provide a connectingdevice, wherein connection is made by merely pressing one member into asecond member.

Another objective of the present invention is to provide a connectionbetween components of an assembly that does not require the use ofextensive and costly machinery, substantial operator skill, solvents oradhesives.

Another objective of the present invention is to provide a connectionfor components of an assembly that may be easily molded from plastic.

The foregoing objectives and advantages of the invention will appearmore fully hereinafter from a consideration of a detailed descriptionwhich follows, taken together with the accompanying drawings, whereinone embodiment of the invention is illustrated by way of example. It isto be expressly understood, however, that the drawings are forillustrative purposes only and are not to be considered as defining thelimits of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective assembly drawingshowing a spool having a barrel and flanges connected by a deviceconstructed in accordance with the laws of the present invention.

FIG. 2 is a fragmentary plan view of a portion of the flange of FIG. 1as seen looking towards the spool.

FIG. 3 is a fragmentary plan view of a portion of the flange as shown inFIG. 2 looking from the barrel.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2.

FIG. 5 is a fragmentary sectional view taken along lines 4-4 of FIG. 2and showing the components being connected.

FIG. 6 is a fragmentary view similar to that of FIG. 5 showing thecomponents after they are connected.

FIG. 7 is a plan view similar to FIG. 2 but shown after connection ofthe barrel to the flange.

DESCRIPTION OF THE INVENTION The present invention will be described inconnection with a spool assembly, wherein flanges 10 are connected tothe ends of barrel 12. The flanges and barrel are molded from a plasticmaterial in a manner well known in the art. Flanges 10 are circularhaving a hub portion 14 located centrally thereof.

Referring to FIG. 2, the hub portion 14 has an inner cylindrical sleeve18 and a plurality of triangular spokes 20 radiating therefrom.Disbursed between triangular spokes 20, are tongue members 22 connectedto the hub adjacent the sleeve and extending radially therefrom. Tongues22 are molded to have a thickness that renders them substantiallyresilient. Spokes 20 are connected to an annular shoulder 24, which issurrounded by a protective wall 26, the purpose of which will bediscussed subsequently.

Referring now to FIGS. 3 and 4, triangular spokes 20 are shownconnecting sleeve 18 to the main body of flange 10 and tongues 22 areshown radiating outward from sleeve 18 between each of said triangularspokes. Reinforcing ribs 28 are formed along the edges of triangularspokes 20 to provide added strength between sleeve 18 and the main bodyof flange l0. Triangular shaped fins 30 are formed integrally withstrengthening ribs 28 and extend outwardly in the same direction assleeve 18. Strengthening posts 32 are formed at the apex of thetriangular spokes 20 for providing added strength at the tip of thespokes.

Referring to FIGS. 3, 4 and 5, the inside of the flange has a flaredannular ridge formed around the periphery of the hub portion 14 by acurved surface 34 and a beveled surface 36. Segments 38, of acylindrical surface, are formed between triangular spokes 20 and connectbeveled surface 36 and shoulder 24. Segments 38 and the ends ofresilient tongue members 22 define arcuate slots 40 for receivingprojections 42 formed on barrel 12.

Referring to FIGS. 1, 3, 4 and 5, barrel 12 has projections 42 extendingfrom each end thereof and positioned for insertion into slots 40 offlanges 10. Barrel 12 is molded from a resilient plastic material sothat projections 42 are yieldable and may be bent towards the center ofbarrel 12. Each projection has an enlarged portion 44 formed on one sidethereof and defined by an inclined or curved surface 46 rising from theoutermost edge of a projection 42 and by lip 48 spaced from the edge ofthe projection. A flared circumferential ridge 50 is formed about theperiphery of barrel 12 by a curved surface 52 and a beveled surface 54.Ridge 50 is spaced from lips 48 to define segments 56 of a cylindricalsurface so that lips 48, beveled surface 54 and segments 56 complementshoulder 24, beveled surface 36 and segments 38 of flanges 10.

The spool is assembled by aligning projections 42 of barrel 12 withslots 40 of flange 10 and by pushing barrel 12 in a direction asindicated by arrow 58 in FIG. 5. Curved surfaces 46 cooperate withbeveled surface 36 of flange 10 to bend projections 42 radially inwardso that the ends of projections 42 engage tongues 22, which yield in thedirection of arrow 45. When curved surfaces 46 and lips 48 pass thecylindrical surfaces 38, projections 42 recover and return to theirnormal unbent positions so that lips 48 engage shoulder 24 and curvedsurfaces 34 and 52 form a smooth fillet between the barrel and flange asshown in FIGS. 6 and 7. When projection 42 returns to its unbentposition, resilient tongues 22 snap back to their normal positions andengage the interior surfaces of projections 42 opposite curved surfaces46 to prevent projections 42 from again bending inwardly. Thus, it maybe seen that tongues 22 lock projections 42 in position so that lips 48engage shoulder 24 preventing the removal of barrel 12 from flange 10.

Outwardly extending protective wall 26 protects projections 42 andtongues 22 from damage that may result from a blow directed towards theoutside of flange 10 and also functions as a guard to preventprojections 42 from catching other objects. Fins 30 extend into barrel12 for supporting the barrel and for relieving the strain that may beexerted on the projections 42 should a force be exerted on either barrel12 or flange 10.

Thus, the present invention provides a device for connecting componentparts of a spool without the need for adhesive and also provides alocking means to prevent subsequent detachment of the connected parts.Connection is accomplished by merely pressing one member into anotherand a separate locking procedure is not required. Assembly time isreduced by the elimination of the locking procedure and by theelimination of the need of adhesive which requires extensive drying timeor the application of heat. Strengthening fins are provided to relievethe strain that would normally be exerted on the connected means. Thecomponents are easily molded from plastic material.

While the invention as described was in a spool embodiment, theteachings of this invention may be easily applied to other types ofassemblies where components are to be connected together, includingcomponents having other than circular shapes, components which cannot berotated relative to each other and components formed of materialsdiffering in composition and characteristics.

What is claimed is:

l. A locking assembly for connecting first and second members,comprising:

at least one opening formed in the first member, said opening beingdefined partially by a rigid edge portion and partially by an end of aresilient tongue formed opposite the rigid edge portion;

a yieldable projection formed on said second member and disposed withinthe opening of the first member, so that the resilient tongue of thefirst member engages the projection of the second member; and

engaging means, formed on the side of the projection adjacent the rigidedge portion, for engaging the rigid edge portion of the first memberand connecting the first and second members, whereby said yieldableprojection and resilient tongue interact and bend to facilitateinsertionof the projection into the opening and thereafter recover sothat the engaging means engage the rigid edge portion and the tongueengages the projection rendering the projection non-yieldable andthereby locking the engaging means in an engaged position.

2. A locking assembly as described in claim 1, wherein the rigid edgeportion includes a beveled edge surface which cooperates with theyieldable projection to facilitate insertion of the projection into theopening.

3. A locking assembly as described in claim 1, additionally comprising:

a support member formed adjacent the resilient tongue of said firstmember and extending towards the second member, so that said supportmember engages said second member at a position along side of theprojection and provides support for said second member therebypreventing excessive force from being exerted on the projection of thesecond member and the resilient tongue of the first member when anexternal force is applied to either of the first or second members.

4. A locking assembly for connecting first and second members,comprising:

a plurality of rigid .edge portions spaced apart and formed in saidfirst member; resilient tongue structures formed integrally with saidfirst member and having ends spaced from the rigid edge portions so thatopenings are defined by the rigid edge portions and the ends of thetongue structures; yieldable projections formed and arranged on saidsecond member for insertion into the openings of the first member; anenlarged portion formed at the end of each projection on a side adjacenta rigid edge portion; and means formed in said rigid edge portions forreceiving the enlarged portions after the projections are inserted intothe openings, whereby the enlarged portions engage the'rigid edgeportions to connect the first and second members and the resilienttongues engage the yieldable projections on sides opposite the enlargedportions to prevent disengagement of the enlarged portions from therigid edge portions. 5. A locking assembly as described in claim 4,wherein each rigid edge portion includes a forward surface and eachenlarged portion includes an inclined surface, said surfaces cooperatingto facilitate insertion of the projections into the openings.

6. A spool including a pair of flanges and a cylindrical barrel, whereinthe improvement comprises:

a plurality of spaced arcuate slots formed about a circle in each of theflanges, the slots being defined on one side by rigid edge portions andon the other side by the ends of resilient tongue structures positionedradially inward from said rigid edge portions;

yieldable arcuate projections formed and arranged about each end of thebarrel for insertion into the slots of the flanges;

enlarged portions formed at the ends of the projections and on sides ofthe projections adjacent the rigid edge portions; and

receiving means formed in said rigid edge portions for receiving theenlarged portions after the projections are inserted into the openings,whereby the enlarged portions engage the rigid edge portions to connectthe flanges to the barrel and the resilient tongue structures engage theprojections on sides opposite the enlarged portions to preventdisengagement of the enlarged portions from the rigid edge portions.

7. 'A spool including a pair of flanges and a cylindrical barrel,wherein the improvement comprises:

a plurality of spaced arcuate slots formed about a circle in each of theflanges, the slots being defined on one side by rigid edge portions andon the other side by the ends of resilient tongue structures positionedradially inward from said rigid edge portions;

strengthening members formed on said flanges adjacent the resilienttongue structures to provide added flange strength adjacent saidtongues;

yieldable arcuate projections formed and arranged about each end of thebarrel for insertion into the slots of the flanges;

enlarged portions formed at the ends of the projections and on sides ofthe projections adjacent the rigid edge portions; and

receiving means formed in said rigid edge portions for receiving theenlarged portions after the projec tions are inserted into the openings,whereby the enlarged portions engage the rigid edge portions to connectthe flanges to the barrel and the resilient tongue structures engage theprojections on sides opposite the enlarged portions to preventdisengagement of the enlarged portions from the rigid edge portions.

1. A locking assembly for connecting first and second members,comprising: at least one opening formed in the first member, saidopening being defined partially by a rigid edge portion and partially byan end of a resilient tongue formed opposite the rigid edge portion; ayieldable projection formed on said second member and disposed withinthe opening of the first member, so that the resilient tongue of thefirst member engages the projection of the second member; and engagingmeans, formed on the side of the projection adjacent the rigid edgeportion, for engaging the rigid edge portion of the first member andconnecting the first and second members, whereby said yieldableprojection and resilient tongue interact and bend to facilitateinsertion of the projection into the opening and thereafter recover sothat the engaging means engage the rigid edge portion and the tongueengages the projection rendering the projection non-yieldable andthereby locking the engaging means in an engaged position.
 2. A lockingassembly as described in claim 1, wherein the rigid edge portionincludes a beveled edge surface which cooperates with the yieldableprojection to facilitate insertion of the projection into the opening.3. A locking assembly as described in claim 1, additionally comprising:a support member formed adjacent the resilient tongue of said firstmember and extending towards the second member, so that said supportmember engages said second member at a position along side of theprojection and provides support for said second member therebypreventing excessive force from being exerted on the projection of thesecond member and the resilient tongue of the first member when anexternal force is applied to either of the first or second members.
 4. Alocking assembly for connecting first and second members, comprising: aplurality of rigid edge portions spaced apart and formed in said firstmember; resilient tongue structures formed integrally with said firstmember and having ends spaced from the rigid edge portions so thatopenings are defined by the rigid edge portions and the ends of thetongue structures; yieldable projections formed and arranged on saidsecoNd member for insertion into the openings of the first member; anenlarged portion formed at the end of each projection on a side adjacenta rigid edge portion; and means formed in said rigid edge portions forreceiving the enlarged portions after the projections are inserted intothe openings, whereby the enlarged portions engage the rigid edgeportions to connect the first and second members and the resilienttongues engage the yieldable projections on sides opposite the enlargedportions to prevent disengagement of the enlarged portions from therigid edge portions.
 5. A locking assembly as described in claim 4,wherein each rigid edge portion includes a forward surface and eachenlarged portion includes an inclined surface, said surfaces cooperatingto facilitate insertion of the projections into the openings.
 6. A spoolincluding a pair of flanges and a cylindrical barrel, wherein theimprovement comprises: a plurality of spaced arcuate slots formed abouta circle in each of the flanges, the slots being defined on one side byrigid edge portions and on the other side by the ends of resilienttongue structures positioned radially inward from said rigid edgeportions; yieldable arcuate projections formed and arranged about eachend of the barrel for insertion into the slots of the flanges; enlargedportions formed at the ends of the projections and on sides of theprojections adjacent the rigid edge portions; and receiving means formedin said rigid edge portions for receiving the enlarged portions afterthe projections are inserted into the openings, whereby the enlargedportions engage the rigid edge portions to connect the flanges to thebarrel and the resilient tongue structures engage the projections onsides opposite the enlarged portions to prevent disengagement of theenlarged portions from the rigid edge portions.
 7. A spool including apair of flanges and a cylindrical barrel, wherein the improvementcomprises: a plurality of spaced arcuate slots formed about a circle ineach of the flanges, the slots being defined on one side by rigid edgeportions and on the other side by the ends of resilient tonguestructures positioned radially inward from said rigid edge portions;strengthening members formed on said flanges adjacent the resilienttongue structures to provide added flange strength adjacent saidtongues; yieldable arcuate projections formed and arranged about eachend of the barrel for insertion into the slots of the flanges; enlargedportions formed at the ends of the projections and on sides of theprojections adjacent the rigid edge portions; and receiving means formedin said rigid edge portions for receiving the enlarged portions afterthe projections are inserted into the openings, whereby the enlargedportions engage the rigid edge portions to connect the flanges to thebarrel and the resilient tongue structures engage the projections onsides opposite the enlarged portions to prevent disengagement of theenlarged portions from the rigid edge portions.